TECHNICAL FIELD
[0001] The present invention relates to an audio transmission system, in particular, to
an audio transmission system that detects a position of a sound source and performs
sound field control to create a high level of presence.
BACKGROUND ART
[0002] In general, a communication conference system is configured such that audio of conference
participants is collected by a plurality of microphones, and is mixed and then transmitted.
On the reception side, the audio is reproduced from all of loudspeakers at an equal
level of sound volume and phase. In the case of such a communication conference system,
the audio data is reproduced with a same sound image regardless of who is speaking
among the conference participants. As a result, it is difficult on the reception side
to identify who spoke.
[0003] Moreover, on the reception side, since the sound volume of a loudspeaker is fixed,
the sound volume from the loudspeaker significantly fluctuates when there is a plurality
of conference participants on the transmission side, due to differences in the audio
sound volume of the respective participants and in the distance between microphones
and the participants.
[0004] Based on such circumstances, there has been proposed a voice telephone conference
device that determines a speaker and the position of the speaker based on the temporal
waveform and the frequency spectrum of a microphone input signal (for example, refer
to
JP-A-09 261351).
[0005] The voice telephone conference device disclosed in
JP-A-09 261351 determines a speaker and the position of the speaker based on the temporal waveform
and the frequency spectrum of a microphone input signal, and transmits position information,
along with audio data. The reception side controls the sound volume of each loudspeaker
based on the received position information. Moreover, there is provided a switch for
switching to select audio data with a highest input level among the respective microphones,
and the reception side is set so that the audio is emitted from the loudspeaker that
corresponds to the microphone that collected the audio.
[0006] However, a sound field with a high level of presence (for example, a feel of depth)
can not be realized by only controlling the sound volumes of the respective loudspeaker
(stereo loudspeaker units) based on the position information.
[0007] Furthermore, each of the microphones is provided with the switch for switching to
select audio data with a highest input level among the respective microphones. However,
there is an issue in that when a plurality of speakers start speaking simultaneously,
this switching needs to be performed in a short period of time, and accurate audio
data cannot be transmitted as a result.
[0008] WO 03/015407A1 discloses a system and method for high resolution video conferencing, and was used
as a basis for the preamble of claim 1. A transmitting station and a receiving station
including video cameras or sensors, a plurality of microphones and speakers, video,
audio, and communication processing engines are disclosed. Video is processed and
transferred through the system allowing for multiple video streams to be produced
and audio is processed and transferred through the system allowing for sound to be
played back with an indication of position in relation to the videoconferencing system.
[0009] WO 97/48252 A1 discloses an acoustic signal processing method and system using a pair of spatially
separated microphones to obtain the direction or location of speech or other acoustic
signals from a common sound source. A method and apparatus is provided for processing
the acoustic signals by determining whether signals acquired during a particular time
frame represent the onset or beginning of a sequence of acoustic signals from the
sound source, identifying acoustic received signals representative of the sequence
of signals, and determining the direction of the source based upon the acoustic received
signals.
DISCLOSURE OF INVENTION
[0010] Therefore, it is an object of the present invention to provide an audio transmission
system that is able to control a sound field having a high level of presence with
a simple configuration.
[0011] An audio transmission system of the present invention is provided as set forth in
claim 1. Preferred embodiments of the present invention may be gathered from the dependent
claims.
[0012] In the present invention, the position of the sound source in the first location
(transmission side) is identified, and the directivity characteristic of microphone
sensitivity is set to point to the identified position. The collected audio data is
transmitted to the second location (reception side) along with the directivity characteristic.
On the reception side, a virtual sound source is formed in the sound source position
on the transmission side, based on the directivity characteristic. For example, when
a speaker in a position in the right side back when seen from the reception side (left
side front on the transmission side) speaks, the audio is reproduced from right side.
[0013] In the present invention, the collected audio data is transmitted, along with its
directivity characteristic, from the first location to the second location, and on
the other hand, the collected audio data is transmitted, along with its directivity
characteristic, from the second location to the first location. In the first location
and the second location, virtual sound sources are formed respectively on the reception
side in the positions corresponding to positions of the sound sources on the transmission
side.
[0014] In the present invention, the position detection device may detect a plurality of
sound source positions; the microphone side signal processing device may set the directivity
characteristic of the microphone array respectively to point to a plurality of the
sound source positions; the information transmission device may transmit a plurality
of audio data along with their respective directivity characteristic information;
the information reception device may receive a plurality of the audio data along with
their respective directivity characteristic information; and the loudspeaker side
signal processing device may set the directivity characteristic of the loudspeaker
array so that virtual sound sources are formed in a plurality of sound source positions.
[0015] In this case, the audio transmission system detects a plurality of the sound source
positions on the transmission side to set the directivity characteristic of microphone
sensitivity. Moreover, this system transmits a plurality of collected audio data along
with their respective directivity characteristics to the reception side. On the reception
side, virtual sound sources are formed respectively on the reception side in a plurality
of the sound source positions corresponding to those on the transmission side, based
on their respective directivity characteristics.
[0016] As described above, according to the present invention, on the transmission side,
the position of a sound source is identified and the directivity characteristic of
microphone sensitivity is set to point to the sound source, and on the reception side,
the directivity characteristic of the loudspeaker array is set so that a virtual sound
source is formed on the reception side in the sound source position corresponding
to that on the transmission side. As a result, a communication conference having a
high level of presence can be realized with a simple configuration.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017]
FIG. 1 is schematic diagram showing a configuration of a communication conference
system according to an embodiment of the present invention.
FIG. 2 is block diagram showing a communication conference device and a terminal unit
according to the embodiment of the present invention.
FIG. 3 is a diagram showing position measurement of the terminal unit shown in FIG.
2.
FIG. 4A is a diagram for explaining a directivity characteristic of a microphone array
on the transmission side in the embodiment of the present invention.
FIG. 4B is a diagram for explaining a directivity characteristic of a loudspeaker
array on the reception side in the embodiment of the present invention.
FIGS. 5A, 5B, 5C, and 5D are diagrams showing examples of transmitted/received packets
used in the embodiment of the present invention.
FIG. 6 is a flow chart showing a position measurement operation in the embodiment
of the present invention.
FIG. 7 is a flow chart showing an operation at the time of conference commencement
in the embodiment of the present invention.
FIG. 8 is a flow chart showing an operation on the transmission side in the embodiment
of the present invention.
FIG. 9 is a flow chart showing an operation on the reception side in the embodiment
of the present invention.
BEST MODE FOR CARRYING OUT THE INVENTION
[0018] FIG. 1 is schematic diagram showing a configuration of a communication conference
system according to an embodiment of the present invention. As shown in FIG. 1, this
communication conference system comprises; communication conference devices 1 that
are installed respectively in a plurality of conference rooms, and terminal units
2 that are carried by respective conference participants.
[0019] The communication conference devices 1 are installed in the respective conference
rooms. The communication conference devices 1 are respectively connected via a network
(LAN or Internet) or a telephone line. The terminal units 2 are remote controllers
that are carried by all conference participants. A conference participant uses this
terminal unit 2 to notify the commencement of a conference. This terminal unit 2 may
be carried by each of conference participants, or it may be installed on a desk. Moreover,
it is not necessary to provide terminal units 2 for all conference participants, and
one or more of the terminal units 2 may to be provided for each conference room.
[0020] FIG. 2 is a block diagram showing a configuration of the communication conference
device 1 and the terminal unit 2. As shown in FIG. 2, the communication conference
device 1 comprises: a microphone array 11 that collects audio; a loudspeaker array
12 that outputs audio; an infrared communication section 13 that communicates with
the terminal unit 2; a control section 14 that controls the communication conference
device 1; and a data transmission/reception section 15 that communicates with other
communication conference devices. The terminal unit 2 comprises: a terminal unit microphone
21 that receives audio input; a terminal unit control section 22 that controls the
terminal unit; a terminal unit infrared communication section 23 that communicates
with the communication conference device 1; and a user interface 24 on which a user
performs operation input.
[0021] The control section 14 of the communication conference device 1 is connected to the
microphone array 11, the loudspeaker array 12, the infrared communication section
13, and the data transmission/reception section 15. Moreover, the terminal unit control
section 22 is connected to the terminal unit microphone 21, the terminal unit infrared
communication section 23, and the user interface 24.
[0022] The control section 14 of the communication conference device 1 controls the directivity
characteristics of the microphone array 11 and the loudspeaker array 12. The microphone
array 11 and the loudspeaker array 12 are configured such that a plurality of microphone
units (loudspeaker units) is arranged in a matrix form (or, in a line form or a honeycomb
form). As a result, their directivity characteristics can be controlled by controlling
their delay amounts.
[0023] For example, if audio is outputted from a loudspeaker unit on an end section first
and then the audio is outputted sequentially from adjacent loudspeaker units with
a predetermined delay time, then the synthesis wave front of these audios inclines
according to their delay time. As a result, a sound beam can be brought to point in
a diagonal direction. Thus, by controlling the delay amounts of the loudspeaker array,
a sound image can be positioned with respect to the conference participants in front
of the communication conference device 1.
[0024] Similarly, in the microphone array, by controlling the delay amounts of the respective
microphone units, microphone sensitivity can be brought to point in a predetermined
direction.
[0025] The control section 14 transmits audio data inputted from the microphone array to
the data transmission/reception section 15. The control section 14 has a built-in
A/D converter as necessary, and transmits the collected audio data to the data transmission/reception
section 15. The data transmission/reception section 15 transmits the audio data to
the data transmission/reception section 15 of the network-connected communication
conference device 1 in another conference room. The data transmission/reception section
15 in another conference room that has received the audio data transmits the audio
data to the connected control section 14. Having received the audio data, the control
section 14 D/A converts the audio data and outputs it to the loudspeaker array 12,
thereby outputting the audio. Thus, the audio emitted from a conference participant
is collected by the microphone array 11, and is emitted from the loudspeaker array
12 in another conference room.
[0026] The terminal unit control section 22 performs various kinds of operation according
to the control inputted from the user interface 24. When a conference participant
notifies the commencement of a conference from the user interface 24, the terminal
unit control section 22 transmits a notification of the conference commencement to
the communication conference device 1 via the terminal unit infrared communication
section 23. The control section 14 of the communication conference device 1 that has
received the notification of conference commencement via the infrared communication
section 13 transmits a connection request to another conference room to the data transmission/reception
section 15. The data transmission/reception section 15 starts communicating with the
data transmission/reception section 15 in another conference room.
[0027] Moreover, when a conference participant instructs a sound volume change from the
user interface 24, the terminal unit control section 22 transmits instruction information
of the sound volume change to the communication conference device 1 via the terminal
unit infrared communication section 23.
[0028] The terminal unit microphone 21 is for receiving sound waves from the communication
conference device 1. The communication conference system of the present embodiment
performs operations as described below. The control section 14 emits sound waves from
any one of the loudspeaker units of the loudspeaker array 12 and starts a counter
(timer). Having received these sound waves via the terminal unit microphone 21, the
terminal unit control section 22 transmits the received signal to the communication
conference device 1 via the terminal unit infrared communication section 23.
[0029] Having received the received signal via the infrared communication section 13, the
control section 14 stops the counter, and measures the distance between the loudspeaker
unit and the terminal unit 2 by measuring the time elapsed from the emission of the
sound waves to the reception of the received signal. Such a distance measurement is
carried out for a plurality of the loudspeaker units, thereby identifying the position
of the terminal unit 2.
[0030] FIG. 3 shows position measurement of the terminal unit in detail. As shown in FIG.
3, on the front face of the communication conference device 1, there are provided
a plurality of (two in FIG. 3) microphone units 11A (and microphone unit 11B) and
a plurality of loudspeaker units 12A (and loudspeaker unit 12B).
[0031] In FIG. 3, reference symbol W denotes a distance between: the center position of
the microphone unit 11A and the loudspeaker unit 12A; and the center position of the
other microphone unit 11B and the loudspeaker unit 12B. Moreover, reference symbol
D denotes a distance between: the center position of one microphone unit 11A and the
loudspeaker unit 12A; and the terminal unit 2, and reference symbol D2 denotes a distance
between: the center position of the other microphone unit 11B and the loudspeaker
unit 12B; and the terminal unit 2. The internal angle at the vertex between W and
D1 is θ.
[0032] This θ can be found by the following equation (1) using the cosine theorem.

[0033] Here, the coordinate of the center position of the communication conference device
1 is (0, 0). Accordingly, the coordinate (X1, Y1) of the position in which the terminal
unit 2 exists is expressed as the following equation (2).

[0034] Thus, the communication conference device 1 can measure the position of the terminal
unit 2. This position measurement is carried out for all of the terminal units 2 if
there are provided a plurality of the terminal units 2. In the case where each of
the conference participants has the terminal unit 2, the position in which each of
the terminal units 2 exists is taken as the positions of the conference participant.
Moreover, in the case where the number of the terminal units 2 is less than that of
the conference participants, or there is one terminal unit 2 present, the above mentioned
position measurement is carried out for the position of each of the respective conference
participants, and the information of each of the measured positions is stored as the
position of the conference participant into a memory (not shown in the diagram) of
the communication conference device 1.
[0035] Position measurement is not limited to the above method, and it may be carried out
by other methods such as identifying a position by image recognition for example.
[0036] Based on the information relating to the position of the terminal unit 2 measured
as described above, the control section 14 controls the directivity characteristic
of the microphone array 11. For example, the directivity characteristic of the microphone
array 11 is set so that the sensitivity of the microphone array 11 points to the position
of the terminal unit 2, thereby efficiently collecting audio of a speaker. Moreover,
for a position far distanced from the communication conference device 1, the gain
of the microphone array 11 is raised.
[0037] Furthermore, the position informations of the respective terminal units 2 (position
information of the conference participants) are transmitted to the communication conference
device 1 in another conference room. The control section 14 of the communication conference
device in another conference room sets the directivity characteristic of the loudspeaker
unit 12 according to the received position information of the terminal unit 2. As
mentioned above, since the coordinate of the position of the terminal unit 2 (conference
participant) on the transmission side can be identified, the directivity characteristic
of the loudspeaker array is controlled to position a sound image so that the audio
appears as if it is emitted from this position coordinate when seen from the reception
side.
[0038] FIG. 4A and FIG. 4B are diagrams for explaining directivity characteristics. FIG.
4A is a diagram showing the directivity characteristic of the microphone array 11
on the transmission side. In FIG. 4A, the audio emitted by a conference participant
reaches the microphone units sequentially from the closest one, and delays are given
to the respective microphone units so that the audio emitted from the sound source
is outputted with the same phase. Since the audio is outputted from the each of the
microphone units with the same phase, the audio is accentuated when these audio data
are mixed. Here, the audio emitted from another position is outputted from each of
the microphone units with a different phase and is therefore offset when mixed. As
a result, the primary sensitivity of the microphone can brought to point to the direction
of the sound source.
[0039] FIG. 4B is a diagram showing the directivity characteristic of the loudspeaker array
12 on the reception side. In FIG. 4B, the received audio data is outputted from each
of the loudspeaker units. At this time, a virtual sound source is formed due to a
positional relationship between the communication conference device 1 and the terminal
unit 2 shown in FIG. 4A. Audio is outputted from the loudspeaker unit in a position
closest to this virtual sound source first, and then it is outputted from the adjacent
loudspeaker units sequentially with delays. As described above, by sequentially giving
delays to the outputs, a sound image can be positioned as if the audio is emitted
from the position of the speaker.
[0040] Data that are transmitted and received between the communication conference devices
1 for carrying out such control are described. FIG. 5A to FIG. 5D are diagrams showing
examples of transmitted/received packets. The communication conference device 1 performs
transmission/reception of packets using TCP/IP. The header portion and the footer
portion shown in these diagrams are headers and footers of TCP/IP (information for
communication control).
[0041] FIG. 5A shows an example of a packet that includes audio data. As shown in FIG. 5A,
the data portion includes position information absence data, position information
X, position information Y, and audio data. The position information absence data is
data that shows whether or not the packet includes position information (position
coordinates) of each of the conference participants mentioned above, and by making
reference to this, the control section 14 of the communication conference device 1
determines whether or not it controls the directivity characteristic of the loudspeaker
array 12. In the case where the position information absence data indicates that the
packet does not include position information, the received audio data are uniformly
reproduced from all of the loudspeaker units.
[0042] The position information X and the position information Y are data that show the
position coordinates of the respective conference participants mentioned above. The
control section 14 controls the directivity characteristic of the loudspeaker array
12 based on this information, thereby positioning a sound image as if the audio is
heard from this position.
[0043] Moreover, position information may be transmitted and received when a conference
is commenced, and information for identifying the respective conference participants
and audio data may be added to the data portion to be transmitted and received during
the conference.
[0044] FIG. 5B is a diagram showing an example of a packet transmitted and received when
a conference is commenced. FIG. 5C is a diagram showing an example of a packet transmitted
and received during a conference. As shown in FIG. 5B, when commencing a conference,
identification information for identifying each of the conference participants and
position information that corresponds to this identification information are transmitted
and received. Having received this packet, the control section 14 stores the identification
information of the respective conference participants and the position information
in the memory with establishing an association or correspondence between them.
[0045] As shown in FIG. 5C, during the conference, identification information for identifying
each of the conference participants and audio data that corresponds to this identification
information are transmitted and received. Having received this packet, the control
section 14 makes reference to the position information in the memory that corresponds
to the received identification information, and controls the directivity characteristic
of the loudspeaker array 12 based on this position information and reproduces the
received audio data.
[0046] In the case where the position of the conference participant has changed during the
conference, a packet that indicates a position information change is transmitted and
received. FIG. 5D shows an example of a packet that indicates a position information
change. As shown in FIG. 5D, in the case where the position of the conference participant
has changed during the conference, position information change data that indicates
that it is a position information change packet, identification information for identifying
the conference participant whose position has been changed, and position information
that corresponds to this identification information are transmitted and received.
Having received this packet, the control section 14 updates the content of the memory
while establishing an association between the received identification information
and the position information.
[0047] In the case where the number of the microphone units in the microphone array on the
transmission side (audio collection side) is equivalent to that in the loudspeaker
array on the reception side (reproduction side) and their array arrangements are the
same (the respective loudspeaker units and the respective microphone units correspond
to each other on a one-to-one basis), then by making the delay amount of the microphone
array the same as that of the loudspeaker array, a sound image can be positioned as
if the audio is emitted from the position of the speaker without transmission/reception
of the position information.
[0048] Next, an operation of the communication conference system of the present embodiment
is described in detail. FIG. 6 is a flow chart showing a position measurement operation.
This operation is performed when a position measurement mode is preliminarily instructed
by a conference participant using the terminal unit 2 before a conference commences.
First, registration information is obtained from the terminal unit 2 (S 10). The registration
information is information that indicates the presence of each of the terminal units
2 and is transmitted from each of the terminal units 2. By receiving this registration
information, the communication conference device 1 can recognize the number of the
terminal units 2 within a conference room. The registration information is stored
in the built-in memory of the communication conference device 1.
[0049] Whether or not the received registration information has been registered within the
memory is determined (S 11), and if the registration information has not been registered,
then it is registered in the memory (S12). If the registration information has been
registered, then the process of s12 is skipped and the flow proceeds to the next process.
[0050] Subsequently, it is determined whether or not a start signal has been received from
the terminal unit 2 (S 13). If the start signal has not been transmitted from the
terminal unit 2, the processing from obtaining the registration information is repeated.
[0051] If the start signal has been transmitted from the terminal unit 2 and this signal
has been received, measurement sound waves are emitted from any one of the loudspeaker
units of the loudspeaker array 12 to start the counter (S 14). These measurement sound
waves may be any type of sound waves. However, for example in this case they are non-audible
sine waves. Subsequently, the terminal unit 2 transmits a sound wave attainment signal
that indicates an attainment of the sound waves from the terminal unit 2 that has
detected the sound waves, and this signal is received and the counter is stopped (S
15). The distance from the terminal unit 2 is thereby measured. Having received the
sound wave attainment signal, the terminal unit 2 is notified of a completion of the
measurement (S 16).
[0052] Then, it is determined whether or not measurement needs to be performed again (S17).
Since the communication conference device 1 manages the number of the terminal units
2 in the conference room when the registration information is obtained, it determines
that a re-measurement is not necessary if the distance from all of the terminal units
2 has been measured. If there is any terminal unit 2, the distance from which has
not been measured, the communication conference device 1 notifies the terminal unit
2 of a start signal transmission request (S18), and then the operation repeats processes
according to a determination of whether or not the start signal has been received
(S18 → S 13). If it is determined that a re-measurement is not necessary, the operation
terminates.
[0053] FIG. 7 is a flow chart showing an operation at the time of commencing a conference.
First, it is determined whether or not a conference start signal has been received
from the terminal unit 2 (S20). This determination process is repeated until the conference
start signal has been received. Once the conference start signal has been received,
it is determined whether or not a position measurement for the terminal unit 2 has
been performed (S21). If a position measurement has not been performed, the packets
that are transmitted/received during the conference are set to not be given position
information (S22). If a position measurement has not been performed, as with a generic
communication conference system, the audios collected by the respective microphone
units are mixed and then transmitted to another conference room so as to be reproduced
from all of the loudspeaker units at a uniform sound volume.
[0054] If a position measurement has been performed, the delay amounts of the respective
microphone units are set based on the position information so that the microphone
sensitivity points to each of the conference participants (S23), and subsequently,
the respective position information and the delay amounts of the respective microphone
units are associated with each other and stored in the memory (S24).
[0055] Next, an operation during a conference is described. FIG. 8 is a flow chart showing
an operation on the transmission side. FIG. 9 is a flow chart showing an operation
on the reception side. In FIG. 8, it is determined whether or not a connection with
the communication conference device 1 on the reception side of another conference
room has been established (S30). If a connection has not been established with the
communication conference device in another conference room, a connection is commenced
(S31). If a connection has been established, the flow proceeds to the next process.
[0056] Subsequently, it is determined whether or not audio has been inputted (S32); and
this process is repeated until audio is inputted. Once audio is inputted, the inputted
audio data and the position information are included in a packet (S33) so as to be
transmitted to the communication conference device 1 on the reception side (S34).
[0057] In FIG. 9, the communication conference device 1 on the reception side receives the
transmitted packet (S40). It is determined whether or not the packet includes position
information (S41). If position information is included, the directivity characteristic
of the loudspeaker array 12 is controlled according to this position information (S42).
Subsequently, the audio is reproduced (S43). If position information is not included,
then the directivity characteristic of the loudspeaker array 12 is not controlled,
and the audio is reproduced from the entire loudspeaker array 12 with a uniform sound
volume and delay amount (S41 → S43).
[0058] In the case where the number of the microphone units in the microphone array on the
transmission side is equal to the number of the loudspeaker units in the loudspeaker
array on the reception side and their array arrangements are the same (the respective
loudspeaker units and the respective microphone units correspond to each other on
a one-to-one basis), by making their delay amount equal to each other, a sound image
can be positioned without transmitting/receiving the position information.
[0059] As described above, in the communication conference system of the present embodiment,
positions of conference participants are identified by measuring the distance between
the communication conference device 1 and the terminal unit 2, and by transmitting/receiving
this position information, a sound image can be positioned on the reception side as
if the speech audio is emitted from the position of the speaker. As a result, a sound
field control with a high level of presence becomes possible. Moreover, in the case
of transmitting/receiving video data of a video telephone or the like, audio can be
controlled so as to appear as if it is emitted from the speaker in the video image,
thereby realising a communication conference system with a further high level of presence.
[0060] Sound image positioning is not limited to the example of the sound image position
control that makes audio appear as if it is emitted from the position of the speaker
on the transmission side. For example, sound image positioning may be performed by
only controlling the sound image position horizontally, without considering the depth
(Y-coordinate) of the sound image.
INDUSTRIAL APPLICABILITY
[0061] The present invention can be applied to an audio transmission system such as a communication
conference system in which sound field control with a high level of presence is performed
by detecting the position of a sound source. According to the present invention, a
communication conference with a high level of presence can be realized with a simple
configuration.
1. An audio transmission system comprising:
a first microphone array (11) having a plurality of microphone units installed in
a first location;
a second loudspeaker array (12) having a plurality of loudspeaker units installed
in a second location;
a first position detection device that detects a first sound source position (X1,
Y1) present in said first location;
a first microphone side signal processing device (14) that sets a first directivity
characteristic of said first microphone array to point to said first sound source
position detected by said first position detection device;
a first transmission device (15) that transmits audio data collected by said first
microphone array with said first directivity characteristic, along with information
of said first directivity characteristic;
a second reception device (15) that is installed in said second location and receives
the audio data transmitted by said first transmission device along with said first
directivity characteristic information; and
a second loudspeaker side signal processing device (14) that sets the directivity
characteristic of said second loudspeaker array based on said first directivity characteristic
information so that a first virtual sound source corresponding to a sound source in
said first sound source position is formed in said second location;
characterized in that
said first position detection device includes at least two loudspeaker units (12A,
12B) for position measurement and a microphone (21) for position measurement located
at said first sound source position, said first sound source position being detected
by measuring times elapsed from emission of sound waves emitted from said loudspeaker
units (12A, 12B) for position measurement to reception of said sound waves received
by said microphone (21) for position measurement.
2. An audio transmission system according to claim 1, further comprising:
a second microphone array (11) having a plurality of microphone units installed in
said second location;
a first loudspeaker array (12) having a plurality of loudspeaker units installed in
said first location, said at least two loudspeaker units (12A, 12B) for position measurement
being included in said first loudspeaker array;
a second position detection device that detects a second sound source position present
in said second location;
a second microphone side signal processing device (14) that sets a second directivity
characteristic of said second microphone array to point to said second sound source
position detected by said second position detection device;
a second transmission device (15) that transmits audio data collected by said second
microphone array with said second directivity characteristic, along with information
of said second directivity characteristic;
a first reception device (15) that is installed in said first location and receives
the audio data transmitted by said second transmission device, along with said second
directivity characteristic information; and
a first loudspeaker side signal processing device (14) that sets the directivity characteristic
of said first loudspeaker array based on said second directivity characteristic information
so that a second virtual sound source corresponding to a sound source in said second
sound source position is formed in said first location.
3. An audio transmission system according to either one of claim 1 and claim 2, wherein:
said first or second position detection device detects a plurality of sound source
positions;
said first or second microphone side signal processing device sets the corresponding
first or second directivity characteristic of said corresponding first or second microphone
array respectively to point to a plurality of sound source positions;
said first or second transmission device transmits a plurality of audio data along
with their respective directivity characteristic information;
said first or second reception device receives a plurality of audio data along with
their respective directivity characteristic information; and
said first or second loudspeaker side signal processing device sets the corresponding
first or second directivity characteristic of said first or second loudspeaker array
respectively so that first or second virtual sound sources are formed in a plurality
of sound source positions.
4. A communication conference device (1) that integrally comprises: said first microphone
array (11) ; said first loudspeaker array (12); said first position detection device
(2, 12A, 12B, 13, 14); said first microphone side signal processing device (14); said
first transmission device (15); said first reception device (15); and said first loudspeaker
side signal processing device (14), according to claim 2.
1. Ein Audio-Übertragungssystem, das Folgendes aufweist:
ein erstes Mikrofonarray (11) mit einer Vielzahl von Mikrofoneinheiten, die in einer
ersten Position installiert sind;
ein zweites Lautsprecherarray (12) mit einer Vielzahl von Lautsprechereinheiten, die
in einer zweiten Position installiert sind;
eine erste Positionsdetektionsvorrichtung, die eine erste Klangquellenposition (X1,
Y1), die in der ersten Position anwesend ist, detektiert;
eine erste mikrofonseitige Signalverarbeitungsvorrichtung (14), die eine erste Richtungscharakteristik
des ersten Mikrofonarrays so einstellt, dass diese auf die erste Klangquellenposition
zeigt, die durch die erste Positionsdetektionsvorrichtung detektiert wurde;
eine erste Übertragungsvorrichtung (15), die Audiodaten, die von dem ersten Mikrofonarray
mit der ersten Richtungscharakteristik gesammelt wurden, zusammen mit Informationen
über die erste Richtungscharakteristik überträgt;
eine zweite Empfangsvorrichtung (15), die in der zweiten Position installiert ist
und die Audiodaten empfängt, die von der ersten Übertragungsvorrichtung zusammen mit
Informationen über die erste Richtungscharakteristik übertragen wurden; und
eine zweite lautsprecherseitige Signalverarbeitungsvorrichtung (14) die die Richtungscharakteristik
des zweiten Lautsprecherarrays basierend auf der ersten Richtungscharakteristikinformation
einstellt, so dass eine erste virtuelle Klangquelle, die einer Klangquelle in der
ersten Klangquellenposition entspricht, in der zweiten Position ausgebildet wird;
dadurch gekennzeichnet, dass
die erste Positionsdetektionsvorrichtung wenigstens zwei Lautsprechereinheiten (12A,
12B) zur Positionsmessung und ein Mikrofon (21) zur Positionsmessung aufweist, das
in der ersten Klangquellenposition angeordnet ist, wobei die erste Klangquellenposition
durch das Messen von verstrichenen Zeiten, von dem Aussenden der Klangwellen, die
von den Lautsprechereinheiten (12A, 12B) zur Positionsmessung ausgesandt werden, bis
zum Empfang der Klangwellen, die von dem Mikrofon (21) zur Positionsmessung empfangen
werden, detektiert wird.
2. Ein Audio-Übertragungssystem nach Anspruch 1, wobei das Übertragungssystem ferner
Folgendes aufweist:
ein zweites Mikrofonarray (11) mit einer Vielzahl von Mikrofoneinheiten, die in der
zweiten Position installiert sind;
ein erstes Lautsprecherarray (12) mit einer Vielzahl von Lautsprechereinheiten, die
in der ersten Position installiert sind, wobei die wenigstens zwei Lautsprechereinheiten
(12A, 12B) zur Positionsmessung in dem ersten Lautsprecherarray enthalten sind;
eine zweite Positionsdetektionsvorrichtung, die eine zweite Klangquellenposition,
die in der zweiten Position vorhanden ist, detektiert;
eine zweite mikrofonseitige Signalverarbeitungsvorrichtung (14), die eine zweite Richtungscharakteristik
des zweiten Mikrofonarrays so einstellt, dass diese auf die zweite Klangquellenposition
zeigt, die durch die zweite Positionsdetektionsvorrichtung detektiert wurde;
eine zweite Übertragungsvorrichtung (15), die Audiodaten, die von dem zweiten Mikrofonarray
mit der zweiten Richtungscharakteristik gesammelt wurden, zusammen mit Informationen
über die zweite Richtungscharakteristik überträgt;
eine erste Empfangsvorrichtung (15), die in der ersten Position installiert ist und
die Audiodaten empfängt, die von der zweiten Übertragungsvorrichtung zusammen mit
Informationen über die zweite Richtungscharakteristik übertragen wurden; und
eine erste lautsprecherseitige Signalverarbeitungsvorrichtung (14) die die Richtungscharakteristik
des ersten Lautsprecherarrays basierend auf der zweiten Richtungscharakteristikinformation
einstellt, so dass eine zweite virtuelle Klangquelle, die einer Klangquelle in der
zweiten Klangquellenposition entspricht, in der ersten Position ausgebildet wird.
3. Ein Audio-Übertragungssystem nach Anspruch 1 oder 2, wobei:
die erste oder zweite Positionsdetektionsvorrichtung eine Vielzahl von Klangquellenpositionen
detektiert;
die erste oder zweite mikrofonseitige Signalverarbeitungsvorrichtung die entsprechende
erste oder zweite Richtungscharakteristiken des entsprechenden ersten oder zweiten
Mikrofonarrays so einstellt, dass diese auf eine Vielzahl von Klangquellenpositionen
zeigt;
die erste oder zweite Übertragungsvorrichtung eine Vielzahl von Audiodaten zusammen
mit deren entsprechenden Richtungscharakteristikinformationen überträgt;
die erste oder zweite Empfangsvorrichtung eine Vielzahl von Audiodaten zusammen mit
deren entsprechenden Richtungscharakteristikinformationen empfängt; und
die erste oder zweite lautsprecherseitige Signalverarbeitungsvorrichtung die entsprechende
erste oder zweite Richtungscharakteristiken des ersten oder zweiten Lautsprecherarrays
entsprechend einstellt, so dass erste oder zweite virtuelle Klangquellen in einer
Vielzahl von Klangquellenpositionen ausgebildet werden.
4. Eine Kommunikationskonferenzvorrichtung (1), wobei die Vorrichtung integriert Folgendes
aufweist: das erste Mikrofonarray (11); das erste Lautsprecherarray (12); die erste
Positionsdetektionsvorrichtung (2, 12A, 12B, 13, 14); die erste mikrofonseitige Signalverarbeitungsvorrichtung
(14); die erste Übertragungsvorrichtung (15); die erste Empfangsvorrichtung (15);
und die erste lautsprecherseitige Signalverarbeitungsvorrichtung (14), gemäß Anspruch
2.
1. Système de transmission audio comprenant :
un premier réseau de microphones (11) comportant une pluralité de microphones installés
dans un premier emplacement ;
un deuxième réseau de haut-parleurs (12) comportant une pluralité de haut-parleurs
installés dans un deuxième emplacement ;
un premier dispositif de détection de position qui détecte une première position de
source sonore (X1, Y1) présente dans le premier emplacement ;
un premier dispositif de traitement de signal côté microphones (14) qui règle une
première caractéristique de directivité du premier réseau de microphones pour pointer
vers la première position de source sonore détectée par le premier dispositif de détection
de position ;
un premier dispositif de transmission (15) qui transmet des données audio recueillies
par le premier réseau de microphones ayant la première caractéristique de directivité,
accompagnées d'informations de la première de caractéristique de directivité ;
un deuxième dispositif de réception (15) qui est installé dans le deuxième emplacement
et reçoit les données audio transmises par le premier dispositif de transmission accompagnées
des premières informations de caractéristique de directivité ; et
un deuxième dispositif de traitement de signal côté haut-parleurs (14) qui règle la
caractéristique de directivité du deuxième réseau de haut-parleurs sur la base des
premières informations de caractéristique de directivité de sorte qu'une première
source sonore virtuelle correspondant à une source sonore dans la première position
de source sonore est formée dans le deuxième emplacement ;
caractérisé en ce que
le premier dispositif de détection de position comprend au moins deux haut-parleurs
(12A, 12B) de mesure de position et un microphone (21) de mesure de position situé
au niveau de la première position de source sonore, la première position de source
sonore étant détectée en mesurant des temps écoulés à partir de l'émission d'ondes
sonores émises par les haut-parleurs (12A, 12B) de mesure de position jusqu'à la réception
des ondes sonores reçues par le microphone (21) de mesure de position.
2. Système de transmission selon la revendication 1, comprenant en outré :
un deuxième réseau de microphones (11) comportant une pluralité de microphones installés
dans le deuxième emplacement ;
un premier réseau de haut-parleurs (12) comportant une pluralité de haut-parleurs
installés dans le premier emplacement, lesdits au moins deux haut-parleurs (12A, 12B)
de mesure de position étant inclus dans le premier réseau de haut-parleurs ;
un deuxième dispositif de détection de position qui détecte une deuxième position
de source sonore présente dans le deuxième emplacement ;
un deuxième dispositif de traitement de signal côté microphones (14) qui règle une
deuxième caractéristique de directivité du deuxième réseau de microphones pour pointer
vers la deuxième position de source sonore détectée par le deuxième dispositif de
détection de position ;
un deuxième dispositif de transmission (15) qui transmet des données audio recueillies
par le deuxième réseau de microphones ayant la deuxième caractéristique de directivité,
accompagnées d'informations de la deuxième caractéristique de directivité ;
un premier dispositif de réception (15) qui est installé dans le premier emplacement
et reçoit les données audio transmises par le deuxième dispositif de transmission,
accompagnées des deuxièmes informations de caractéristique de directivité ; et
un premier dispositif de traitement de signal côté haut-parleurs (14) qui règle la
caractéristique de directivité du premier réseau de haut-parleurs sur la base des
deuxièmes informations de caractéristique de directivité de sorte qu'une deuxième
source sonore virtuelle correspondant à une source sonore dans la deuxième position
de source sonore est formée dans le premier emplacement.
3. Système de transmission audio selon l'une ou l'autre des revendications 1 et 2, dans
lequel :
le premier ou le deuxième dispositif de détection de position détecte une pluralité
de positions de source sonore ;
le premier ou le deuxième dispositif de traitement de signal côté microphones règle
la première ou la deuxième caractéristique de directivité correspondante du premier
ou du deuxième réseau de microphones correspondant respectivement pour pointer vers
une pluralité de positions de source sonore ;
le premier ou le deuxième dispositif de transmission transmet une pluralité de données
audio accompagnées de leurs informations de caractéristique de directivité respectives
;
le premier ou le deuxième dispositif de réception reçoit une pluralité de données
audio accompagnées de leurs informations de caractéristique de directivité respectives
; et
le premier ou le deuxième dispositif de traitement de signal côté haut-parleurs règle
la première ou la deuxième caractéristique de directivité correspondante du premier
ou deuxième réseau de haut-parleurs respectivement de sorte que la première ou la
deuxième source sonore virtuelle est formée dans une pluralité de positions de source
sonore.
4. Dispositif de communication en conférence (1) qui comprend en un seul bloc : le premier
réseau de microphones (11), le premier réseau de haut-parleurs (12), le premier dispositif
de détection de position (2, 12A, 12B, 13, 14) ; le premier dispositif de traitement
de signal côté microphones (14) ; le premier dispositif de transmission (15) ; le
premier dispositif de réception (15) ; et le premier dispositif de traitement de signal
côté haut-parleurs (14), selon la revendication 2.